First of all, there have been enough games played that I doubt there is a bug, but I could not explain what I observed.

I was in Expert mode, playing out speculative branches of a game I am playing with hanuman. I got to a situation in which I wanted to have an elephant commit suicide. It went into the c6 trap on the third step of its move, but the client would not let me complete a pull of a silver rabbit into d6 as the fourth step.

As part of the move, a gold rabbit had been lost as the second step of the turn was moving the gold elephant away from the f6 trap where a gold rabbit resided. The elephant was the only friendly adjacent to the trap.

Am I not understanding something? I understand that pulls can be completed by captured pieces. I also verified this experimentally with other pieces in less unusual circumstances.

There are a few known bugs in similar situations, where the client can become confused by a capture mid-turn, though I don't think I've seen this exact one before. Since this is a postal and anyway the attempted move is an explicit admission of loss, it's not too big of a deal- in desperation you can try using another of the clients (Settings > Game Client, in the gameroom), or sending the move artificially with the blindfold play script.

I was able to confirm that in this particular position, the move can be sent with the flash v1 client, but not with the flash v2 or javascript clients, and the server accepts the move as legal. (Indeed, I don't know of any positions where the server incorrectly assesses the legality of a move, but I also haven't tested these edge cases much at all due to the inconvenience of so doing.)

Yes, looks like it is bug. I just looked at the code and I see what is causing it. But this is a good opportunity to see if we have any other programmers here who can find it. Just open the link that clyring gave above. Hit Ctrl-u to view the source. Click the link to open arimaa.js. All the client code is in this file and source is readable. See if you can find what might me causing the silver rabbit to not be "pullable"

All this moves have in common: - the gold rabbit is captured passiv with first step - the gold elephant captures itself with third step - the 4th step pull by captured elephant is not allowed (- all 4 steps are used not neccessary; reproduced bug with 3 steps in other position)